powertop suggests to remove g-p-m

[Nicolò Chieffo]

Binary package hint: gnome-power-manager

the new intel utility powertop suggests to remove gnome-power-manager:

Suggestion: Disable or remove 'gnome-power-manager' from your system.
Despite its name, some versions of gnome-power-manager end up costing more power
than it'll ever save.

The website http://www.linuxpowertop.org/known.php also suggests to remove gnome-screensaver

[jcfp (jcfp)]

Thank you for your report. I don't see any package for powertop in the ubuntu repositories. How exactly does this suggestion by the powertop developers constitute a bug in the gnome-power-manager package?

[Nicolò Chieffo (yelo3)]

I should have written that I'm using gutsy.
If you don't know what powertop is, it is a new intel utility that
discovers which process drains the battery life

this is the site: http://www.linuxpowertop.org

[Thomas Leonard (talex5)]

Stracing it, it looks like the main culprit is this (in gnome-power-manager-2.18.2/src/gpm-dpms.c):

static void
gpm_dpms_init (GpmDpms *dpms)
{
 dpms->priv = GPM_DPMS_GET_PRIVATE (dpms);

 add_poll_timer (dpms, 500);
}

This wakes up the CPU twice a second to check the monitor's DPMS state.

[Richard Hughes (richard-hughes)]

Just update to 2.18.3, I've made the poll less aggressive.

[Nicolò Chieffo (yelo3)]

I think that there should be a communication between powertop
developers and gnome-power-manager developers... It is useless to make
a software to save power if it does not save power...

[Richard Hughes (richard-hughes)]

>It is useless to make a software to save power if it does not save power

It does save power. The real problem was that DPMS does not give async events on chance, therefor we had to poll. Now the X guys are using xrandr for per-head DPMS we can do this without polling at all. Update g-p-m and watch the recommendation go away.

[Nicolò Chieffo (yelo3)]

ok thanks for the explanation

[Vadim Peretokin (vperetokin)]

While g-p-m was fixed, powertop still gives the recommendation to kill it once in a while.

And if you do kill it, then the suspend/resume/reboot menu's go away.

[Paul Rensing (paulrensing)]

I see the same thing (Ubuntu 8.10, powertop 1.10-1, gnome-power-manager 2.24.0-0ubuntu8.1). You only see it if you follow up on the other suggestions powertop makes first.

You can definitely see the issue. In powertop's stats, gnome-power-manager is responsible for ~20% of the wake-ups, second only to my wireless card. This is with a fairly quiet system.

[Flavio Tordini (zarlino)]

Yes, that still happens in intrepid and actually powertop sometimes reports that gnome-power-manager does many wakeups.